Kaepernick is the trailblazer for what have become silent protests during the national anthem at NFL games as a means of drawing attention to social justice issues and inequality.

Ali's widow, Lonnie Ali, said of Kaepernick: "I am proud to be able to present this to Colin for his passionate defense of social justice and civil rights for all people. Like Muhammad, Colin is a man who stands on his convictions with confidence and courage, undaunted by the personal sacrifices he has had to make to have his message heard. And he has used his celebrity and philanthropy to the benefit of some of our most vulnerable community members."

At age 30, Kaepernick hasn't played in an NFL game since Week 17 of last season after opting out of his contract with the San Francisco 49ers.

"This is not something that I am going to run by anybody. I am not looking for approval. I have to stand up for people that are oppressed ... If they take football away, my endorsements from me, I know that I stood up for what is right," Kaepernick said.

I’d like to lobby @CityofCleveland to make 7/3 an official holiday where the city government is closed, banks are closed, mandatory day off for all workers. It only make sense to roll into America’s birthday with a little pre-game holiday for all on the 3rd. Retweet if you agree https://t.co/LnyACOA6xH